In oil production, it is common to locate an oil storage tank at an oil well site to produce hydrocarbons from the well directly into the oil storage tank. It is also known to provide a propane burner which directs exhaust into a burner tube extending into the oil storage tank for heating oil in the tank. Heating the oil assist in settling sand out of the oil to the bottom of the tank and assists with fluidity of the oil when subsequently pumping the oil into transport tanker trucks.
Occasionally oil is pumped from the oil storage tank into tanker trucks such that the level of oil in the storage tank falls below the elevation of the burner tube in the storage tank. The burner tube in this instance can become excessively hot such that there is danger of igniting volatile hydrocarbons in gaseous form surrounding the burner tube. Ignition of the fumes can cause explosions which damage the tank and are a safety concerns for operators of the storage tank or tanker trucks.
U.S. Pat. No. 7,726,298 by St. Denis discloses a method and apparatus for heating a liquid storage tank in place of a conventional burner tube. An engine is disposed in an engine compartment appended to a peripheral sidewall of the tank and an exhaust conduit extends into the interior of the liquid storage tank from the engine such that heat from hot exhaust gases passing through the exhaust conduit heats the interior of the liquid storage tank. The exhaust conduit can still become excessively hot and is in direct contact with volatile hydrocarbons in the storage tank such that the same risk of ignition and explosions as noted above remains present.